Asus RT-AC1750 B1 Stops Transmitting 5Ghz Wifi

[dwp]

I have had an Asus RT-AC1750 B1 on standard AsusWRT 3.0.0.4.386_51733 running at a friend's house for many months now. Until last night it has been working quite well and devices connected to both 2.4 and 5Ghz without troubles.

I have no idea what happened but suddenly there was a loss of all connectivity and my friend, quite reasonably, powered off both his cable modem and the router. After powering on the cable modem then the router, connectivity was restored. However, there is no 5Ghz wifi available. I have looked for using both a Samsung S22 and a Windows 10 laptop (both of which previously connected via 5Ghz without problems). The 5Ghz SSID (same as the 2.4 but with 5G appended) is simply not showing.

I checked the router's settings via the web interface and all seems fine. I tried toggling the 5Ghz radio off and back on. I tried rebooting the router. Nothing has brought back the 5Ghz that was previously just fine!

I hope that someone can suggest what to do in order to re-establish the 5Ghz signal.

Thanks

 

[ColinTaylor]

Probably a hardware failure.

If you go to System Log - Wireless Log do you see the 5GHz band there?

 

[dwp]

Probably a hardware failure.

If you go to System Log - Wireless Log do you see the 5GHz band there?

I am not sure. I definitely see the 2.4Ghz. So maybe not in there.

I am supposing it might be a hardware failure of some sort. It just seems so odd that it should happen so suddenly and that the 2.4Ghz is fine. Thanks

 

[ColinTaylor]

I had a similar (but not exactly the same) hardware failure recently on my RT-AC68U, which is from the same era as your router. Basically, they're getting old now and prone the failures.

You could try doing a factory reset. If that doesn't help then post the System Log - General Log and System Log - Wireless Log for us to look at.

 

[Tech9]

I am not sure. I definitely see the 2.4Ghz.

The radios have their own hardware with separate power circuits, ICs and power amps. One of them failing is the most common situation. This router model (also known as RT-AC66U B1) has 2x BCM4360 inside in 2.4GHz b/g/n and 5GHz an/ac configuration.